California Avocado Society 1941 Yearbook 26: 45
Psyllid Galls On Avocado
N. Stahler
University of California, Berkeley
On January 7, 1941, the writer discovered large numbers of psyllid galls on avocado
leaves in an orchard at Hacienda Santa Engracia, Mexico, 165 miles south of Monterey.
The severity of the infestation varied considerably, but in some cases many leaves were
entirely transformed into a series of conical erect galls, about 8 mm. long, each
containing a single nymph.
Mr. H. H. Keifer is of the opinion that the insect concerned is Trioza keobelei Kirkaldy,
which Crawford (1914) recorded from Cuernavaca, about 50 miles south of Mexico City.
The present record brings this potential pest much closer to the American border.
—Bulletin. Calif. State Dept. of Agriculture.